Now a hands up, in that this question is actually in relation to DNN Pro, I know this is not the place but I will be asking DNN support as well,  but I need a quick solution, so knowing there are many super smart guys on here I am posting in case someone can provide a clue to help.

I hope this all makes sense, we have just migrated our websites both DNN Community and Pro to a new 2016 virtual server, All the sites are displaying well except?.

Our main web site with a number of child portals i.e https://www.maindomain/  has about 200 editors with a mix of Content Editors and Content Mangers roles. 
They can login but do not get any editing toolbars or options to do anything. it even shows the role name in the profile although to all purposes it looks like login has failed.

the administrators role is ok

Some of the child portals off this domain https://www.maindomain/childportal are ok, but others have the same role problem which is very odd.

All the other portals with their own domains are ok.

I have tried adding the roles again to test users but no change...does anyone know anything we can try